I think the issue here is percentages. As you mentioned earlier, women who survived childbirth, accidents and epidemics could be expected to produce children for years and years before hitting their late 30’s-40’s. That means the vast majority of the population was born earlier in their mothers’ lives. Since so many women today put off motherhood until that borderline-risk age, that large pool of people born to young mothers is shrinking. Therefore the percentage of children with autism is climbing. Not because there is more of some mystery ingredient floating around but because there are fewer children born to young mothers who would otherwise be keeping the ratios constant.
I’ve thought about that as well. Those kids would be devlishly easy to find in previous census reports. In one census you’d have the 20yr old unmarried (statistically male) child living at home with parents. Next census would be the 30yr old unmarried male living at home with parents. Next census would likely find him, at age 40, living with a sibling. In the rural south families didn’t put kin in ‘the home’. They took care of them.
Can’t find more than 2 or 3 of those kids in my family tree research. And I’ve looked at literally hundreds of families and thousands of offspring. One of them was my great aunt. Too long in the birth canal at a (kitchen scale weight) of 12+lbs and her mother’s firstborn to boot. Lived with her parents till they became too old to care for her then lived with siblings. I knew her when I was younger. Definitely not autistic. Just a 4 or 5yr old her entire life. Made eye contact, talked, played with her dolls and did simple household tasks. Was potty trained at 2 or 3yrs old even. Friendly even. Loved to have ‘company’, just like most 4 or 5yr olds. In previous non pc times she was referred to as retarded.
Of her great grandfathers 1200+ great grandchildren she’s the only one I’ve found that did NOT either perish in childhood (and not always from dread disease. snakebite, ‘infection’, and fire did a number on kids as well) or get killed in a war that failed to marry and have children.
My great aunt who’s 95yrs young has never seen a generation of little boys that fail to make eye contact. And in our community it’s the RARE exception of a woman that fails to have children by age 30. Most of them have 2 or 3 by age 25. Still with the little boys and no eye contact though.